Be sure to take a close look under fluorescent lights. They reveal all. When I buy a new vehicle, there are typically tell-tale signs of having been washed with a brush (gasp) or a dirty wash mitt (ugh) and dried with terry towels (kill me now). You'll want to correct all that damage before applying a sealer.
I love my Porter Cable random-orbital. I use it with Lake Country pads (orange for correction, red for wax / sealant application). I've had great luck with Meguiars Ultimate Polish (or Ultimate Compound for more serious issues) to get the swirls out, but there are plenty of products out there to choose from. Once you're removed all the flaws, seal it up.
Final recommendation: Use a spray sealer as a drying aid, which reinforces the sealer you applied, resists abrasion, and keeps crud from sticking between washes. I use, and REALLY like Renny Doyle Double Black Bead Maker during every wash, but there is a lot to choose from. Experiment to find the one you like. I find the "Spray Wax" from various supermarket brands tend to streak, making them harder to use as a drying aid. Using these products as a drying aid has reduced the need for frequent 'waxing'.
Also, if it isn't microfiber, it shouldn't be touching your paint. From the wash mitt, to the drying towels, to the sealer removal towels....ALL microfiber.